triac replacing transformer is it possible????????????

[phoenix87]

hi, every body i have a very wierd idea i.e replacing a transformer with a triac or a group of triacs ......
I know it sounds stupid but wat problem will i face if i do so ...... say i change the firing angle of a triac so that it gives 50V o/p from a 220V mains then rectify it using bridge rectifier and use caps to smoothen the supply.......... then can i use it for power amps??????

kindly help me out is it even possible ?????
1.wat problem will i face ????
2. wat will be the limiting factor ???????




regards
aniket

[Eva]

Theoretically it is possible, however, it's far from practical for 2 reasons:

- There is no galvanic isolation between mains line and amplifier ground. Isolation would be required at any amplifier input and maybe at the output too for safety. Amplifier ground can become 230V AC when phase and neutral are reversed, or 120V AC in balanced power systems (two 120V AC phases 180 degree apart). This is just not allowable for consumer equipment.

- The charging pulses produced by the triac would be very narrow, resulting in high disturbance in the mains line and high stress in the storage capacitors. Electromagnetic interference may also result, like it happens in many triac lighting systems, adding "buzz" noise to the audio.

So there are more contras than pros, and it's potentially very unsafe, particularly if you are unexperienced in working with mains voltage.

Note that forum rules don't allow to discuss such dangerous practices (from the point of view of DIY).

[luka]

just don't do it, even if you would use full mains voltage for amp, do not do this, its not worth your life or life of someone else if something is not done right...

[Salas]

Thread closed due to discussion of dangerous practices.